Aleksi Šedo | Charles University, Prague (original) (raw)
Papers by Aleksi Šedo
PubMed, 1995
A series of C-terminal linear endothelin analogues were prepared and their activities in C6 rat g... more A series of C-terminal linear endothelin analogues were prepared and their activities in C6 rat glioma cell line were tested. Among the synthetic analogues, IBDP 064, Fmoc-Leu-Asp-Ile-Ile-Trp-OH, was the most potent and selective inhibitor of endothelin-3-induced cell proliferation. Its action was comparable with that of the previously described peptide IRL 1038, [Cys11-Cys15]-ET-1(11-21), an ETB specific inhibitor.
PubMed, Jul 1, 2012
γ-Glutamyltranspeptidase (GGT, syn. γ-Glutamyltransferase) and dipeptidylpeptidase-IV (DPP-IV) ac... more γ-Glutamyltranspeptidase (GGT, syn. γ-Glutamyltransferase) and dipeptidylpeptidase-IV (DPP-IV) activity participates in metabolic and growth control of normal and tumor cells by processing biologically active peptides. Here, we report on up-regulation of these enzymes in human brain gliomas determined by catalytic enzyme histochemistry and immunocytochemistry. Higher activity of GGT was found in 50%, 68% and 81% of WHO grade II, III and IV tumors, respectively. The process started at/near the microvasculature, from where it spread to the parenchyma. On average, the enzyme activity in grade II, III and IV gliomas exceeded controls 2.0, 3.0 and 3.5-fold, respectively. Up-regulation of DPP-IV-like activity also started at the microvasculature, but mainly in pericytes and mononuclear-like cells around the vessels and dispersed in the parenchyma. Marked elevation of this enzyme activity, comprising also tumor parenchyma, occurred only in grade IV glioblastomas (65% patients; 3.6 times above controls) which can, therefore, help in their differentiation from grade III gliomas. The increase of total DPP-IV-like activity also included its two enzymatic homologs, the canonical DPP-IV/CD26 and FAP-1α. The increase in GGT is supposed to be a tumor grade dependent response of microvasculature and tumor astrocytes to stress induced by tissue hypoxia and/or the metabolic aberrancies. The increase in DPP-IV-like activity in high-grade tumors can be attributed to inflammatory/scavenging processes performed by the mononuclear-like cells and, in glioblastomas, also to regressive changes in the structure and function of the microvasculature and tumor parenchyma, including astrocyte stress response. The inverse relationship between DPP-IV-like activity and Ki67 in most glioblastomas and shorter survival time of patients with low activity of this enzyme also suggest its anti-oncogenic effects.
Neuro-Oncology
BACKGROUND Brain metastases (BM) are a common complication of oncologic disease associated with d... more BACKGROUND Brain metastases (BM) are a common complication of oncologic disease associated with dismal prognosis and there is an urgent need for novel therapeutic approaches. Fibroblast activation protein (FAP), a transmembrane serine protease, is an emerging theranostic target in cancer due to its frequent upregulation in the tumour microenvironment. FAP protein itself and/or FAP+ cells were shown to promote cancer progression in several extracranial malignancies. However, very little is known about the expression of FAP and the role of FAP+ cells in the unique microenvironment of BM. In this study, we quantified FAP expression and characterized FAP+ cells in BM of various origin. MATERIAL AND METHODS FAP enzymatic activity and protein concentration were determined in samples of BM (n=58) and control non-tumorous brain tissue (n=12) by an enzymatic assay using a specific fluorogenic substrate, western blot, and ELISA. Expression of FAP and the characteristics of FAP+ cells were ana...
Biomarker research, Feb 1, 2024
Small noncoding RNAs play an important role in various disease states, including cancer. PIWI pro... more Small noncoding RNAs play an important role in various disease states, including cancer. PIWI proteins, a subfamily of Argonaute proteins, and PIWI-interacting RNAs (piRNAs) were originally described as germline-specific molecules that inhibit the deleterious activity of transposable elements. However, several studies have suggested a role for the piRNA-PIWI axis in somatic cells, including somatic stem cells. Dysregulated expression of piRNAs and PIWI proteins in human tumors implies that, analogously to their roles in undifferentiated cells under physiological conditions, these molecules may be important for cancer stem cells and thus contribute to cancer progression. We provide an overview of piRNA biogenesis and critically review the evidence for the role of piRNA-PIWI axis in cancer stem cells. In addition, we examine the potential of piRNAs and PIWI proteins to become biomarkers in cancer.
Background: Dipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of se... more Background: Dipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of several autoimmune diseases. The aim of this study was to evaluate the association of DPP-IV presence in blood plasma and mononuclear cells with the disease activity in rheumatoid arthritis (RA). Methods: Patients with active RA (n = 27) were examined at the study enrolment and a follow-up examination was performed after the regression of the joint effusions and at least 6 months after the first investigation. The control group comprised patients with a noninflammatory joint disease, i.e. osteoarthritis (OA; n = 15). The DPP-IV-like enzymatic activity was measured by a kinetic fluorimetric method, the concentration of DPP-IV in the blood plasma was determined using ELISA and the expression of DPP-IV in leukocytes was assayed by flow cytometry. Results: Blood plasma DPP-IV-like enzymatic activity (median ± SD 220.15 ± 83.6 pkat/mL in RA vs. 376.9 ± 144.9 pkat/mL in OA, p < 0.001) and concentrations (median ± SD 465.1 ± 215.6 ng/mL in RA vs. 953.3 ± 368.4 ng/mL in OA, p < 0.001) were lower in patients with active RA compared to OA. In RA patients, the blood plasma DPP-IV-like enzymatic activity negatively correlated with the CRP concentration (r = −0.39, p = 0.044). No significant differences were observed in the DPP-IV-like enzymatic activity and DPP-IV expression in blood mononuclear cells between the RA and OA groups. At follow-up, 18 RA patients had a less active disease as demonstrated by an improved DAS28 score. In this group, comparison of the entry and the follow-up values in individual patients revealed an increase of the blood plasma DPP-IV-like enzymatic activity (median ± SD 141 ± 46 % of the patient's entry values, p = 0.011) and DPP-IV concentration (median ± SD 168 ± 25 %, of the patient's entry values, p = 0.033). In contrast to the blood plasma, the DPP-IV expression in blood mononuclear cells was reduced in these patients as evidenced by a decrease in the cell surface DPP-IV-like enzymatic activity as well as the median fluorescence intensity of DPP-IV staining in lymphocytes (median ± SD 66 ± 56 %, p = 0.018 and 63 ± 31 % of the patient's entry values, p = 0.005, respectively). Conclusions: The association between RA activity and the changes in blood plasma and blood mononuclear cell DPP-IV in individual patients supports the possible relationship of DPP-IV to RA pathophysiology.
Východiska: Multiformni glioblastom (GBM) je nejcastěji se vyskytujici intrakranialni malignitou ... more Východiska: Multiformni glioblastom (GBM) je nejcastěji se vyskytujici intrakranialni malignitou astrocytarniho původu u dospělých. Toto nadorove onemocněni je charakterizovano infaustni prognozou, ktera je způsobena předevsim znacnou rezistenci k adjuvantni terapii souvisejici do znacne miry s přitomnosti glioblastomových kmenových buněk (GSC). Cilena regulace GSC by mohla být novým terapeutickým přistupem vedoucim k překonani rezistence a lepsi prognoze u pacientů s GBM. Jednim z přistupů jak uspěsně ovlivňovat biologii GSC je jejich regulace skrze mikroRNA (miRNA). Tyto kratke nekodujici RNA molekuly posttranskripcně reguluji expresi vice než 2/3 vsech lidských genů, ktere jsou mimo jine zapojeny v regulaci signalnich drah asociovaných s kmenovými buňkami. Navic deregulace exprese některých miRNA byla pozorovana u mnoha nadorů, vc. GBM. Material a Metody: Pomoci technologie GeneChip miRNA 4.0 Array (Affymetrix) jsem provedli globalni expresni analýzu miRNA u 10 parových primarnich buněcných GBM linii derivovaných jednak v bezserových podminkach a v mediu s přidavkem 10 % FBS. Výsledky: Analýza Sox-2 pozitivnich a negativnich parových GBM buněcných linii odhalila 431 odlisně exprimovaných miRNA, přicemž 51 miRNA vykazovalo významnost nižsi než 0,001. U 25 miRNA byla pozorovana zvýsena a u 26 miRNA naopak snižena exprese v Sox-2 pozitivnich buňkach. Nasledně bylo zjistěno, že miR-192-5p a miR-885-5p predikovaly přeživani u pacientů s GBM. Nizka exprese miR-192-5p byla významně asociovana jak s delsim casem do progrese onemocněni (PFS) (0,003; log-rank test), tak s celkovým přeživanim (OS) pacientů s GBM (0,010; log-rank test). Kombinace exprese miR-192-5p a miR-885-5p pak byla schopna stratifikovat pa cienty na zakladě jak PFS, tak OS mnohem přesněji (PFS 0,007 a OS 0,008; log-rank test), než tomu bylo v připadě samotne miR-195-5p. Zavěr: GSC jsou obecně považovany za jednu z přicin rezistence GBM ke konvencni terapii. Zjistili jsme, že expresni hladiny miR-192-5p a miR-885-5p jsou zvýseny v Sox-2 pozitivnich GBM buňkach, což naznacuje jejich možne zapojeni do regulace GSC. Exprese obou těchto miRNA rovněž významně koreluje s přeživanim pa cientů s GBM. Tyto data tedy naznacuji, že miR-192-5p a miR-885-5p mohou být nejen prognostickými markery, ale take slibnými terapeutickými cili u pacientů s GBM.
Kluwer Academic Publishers eBooks, Dec 29, 2005
BMC Musculoskeletal Disorders, Sep 9, 2015
Background: Dipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of se... more Background: Dipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of several autoimmune diseases. The aim of this study was to evaluate the association of DPP-IV presence in blood plasma and mononuclear cells with the disease activity in rheumatoid arthritis (RA). Methods: Patients with active RA (n = 27) were examined at the study enrolment and a follow-up examination was performed after the regression of the joint effusions and at least 6 months after the first investigation. The control group comprised patients with a noninflammatory joint disease, i.e. osteoarthritis (OA; n = 15). The DPP-IV-like enzymatic activity was measured by a kinetic fluorimetric method, the concentration of DPP-IV in the blood plasma was determined using ELISA and the expression of DPP-IV in leukocytes was assayed by flow cytometry. Results: Blood plasma DPP-IV-like enzymatic activity (median ± SD 220.15 ± 83.6 pkat/mL in RA vs. 376.9 ± 144.9 pkat/mL in OA, p < 0.001) and concentrations (median ± SD 465.1 ± 215.6 ng/mL in RA vs. 953.3 ± 368.4 ng/mL in OA, p < 0.001) were lower in patients with active RA compared to OA. In RA patients, the blood plasma DPP-IV-like enzymatic activity negatively correlated with the CRP concentration (r = −0.39, p = 0.044). No significant differences were observed in the DPP-IV-like enzymatic activity and DPP-IV expression in blood mononuclear cells between the RA and OA groups. At follow-up, 18 RA patients had a less active disease as demonstrated by an improved DAS28 score. In this group, comparison of the entry and the follow-up values in individual patients revealed an increase of the blood plasma DPP-IV-like enzymatic activity (median ± SD 141 ± 46 % of the patient's entry values, p = 0.011) and DPP-IV concentration (median ± SD 168 ± 25 %, of the patient's entry values, p = 0.033). In contrast to the blood plasma, the DPP-IV expression in blood mononuclear cells was reduced in these patients as evidenced by a decrease in the cell surface DPP-IV-like enzymatic activity as well as the median fluorescence intensity of DPP-IV staining in lymphocytes (median ± SD 66 ± 56 %, p = 0.018 and 63 ± 31 % of the patient's entry values, p = 0.005, respectively). Conclusions: The association between RA activity and the changes in blood plasma and blood mononuclear cell DPP-IV in individual patients supports the possible relationship of DPP-IV to RA pathophysiology.
Cancers, Apr 21, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
InTech eBooks, Feb 27, 2013
Biological Chemistry, 1998
... The pH activity profiles with GP-NHMec, which were completely inverse to the pro-files of DPP... more ... The pH activity profiles with GP-NHMec, which were completely inverse to the pro-files of DPP-II from cultured normal rat glial cells (Stevens et a/., 1987) and rat brain (Mentlein and Struckhoff, 1989 ... Kreisel, W., Heussner, R., Volk, B., Büchsel, R., Reutter, W., and Grok, W. (1982 ...
The International Journal of Biochemistry & Cell Biology, Mar 1, 2004
... Petr Bu ek , Radek Malík and Aleksi edo Corresponding Author Contact Information , E-mail The... more ... Petr Bu ek , Radek Malík and Aleksi edo Corresponding Author Contact Information , E-mail The Corresponding Author , E-mail The ... Interestingly, glycosylation seems to be a prerequisite for enzymatic activity of human recombinant NAALADase ([Barinka et al., 2002]), although ...
Biochemical Society Transactions, 2000
Neuro-Oncology, Sep 1, 2021
![Research paper thumbnail of [Early detection of sporadic pancreatic cancer]](https://attachments.academia-assets.com/111917798/thumbnails/1.jpg)
](PubMed, Feb 24, 2016
Pancreatic cancer (PC) behaves very differently in comparison with other malignancies. Its preval... more Pancreatic cancer (PC) behaves very differently in comparison with other malignancies. Its prevalence continuously increases, mortality does not decrease, diagnosis is frequently late, radical surgery is limited to 15-20 % of patients, postoperative relapses are frequent, and chemotherapy has a palliative character. Preventive programs are the only possibility of improvement. In familial pancreatic cancer (FPC) the knowledge of the genetic mutation enables earlier entry of specialists into the surveillance program. The repeated use of high resolution imaging methods (including endoscopy and pancreatic cytology) may be followed by more frequent detection of the precursors and earlier stages of FPC. The identification of sporadic pancreatic cancer (SPC) depends fully on the construction of a multi-step and multi-disciplinary preventive program.
![Research paper thumbnail of Quaternary benzo[c]phenanthridine alkaloids as inhibitors of dipeptidyl peptidase IV-like activity bearing enzymes in human blood plasma and glioma cell lines](https://attachments.academia-assets.com/108133980/thumbnails/1.jpg)
](Physiological Research, 2003
Quaternary benzo[c]phenanthridine alkaloids (QBA), fagaronine (FA), sanguinarine (SA), chelerythr... more Quaternary benzo[c]phenanthridine alkaloids (QBA), fagaronine (FA), sanguinarine (SA), chelerythrine (CHE) and the QBA extract from Macleya cordata (EX) exerted differential inhibitory effect on the hydrolytic activity of particular dipeptidyl peptidase (DPP)-like enzyme isolated from human blood plasma and from human and rat glioma cell lines. The low-MW form of DPP-IV-like enzyme activity, corresponding most probably to DPP-8, observed only in glioma cells but not in human plasma, was inhibited preferentially by SA, CHE and EX, and only slightly by FA. The alkaloid inhibitory effect was concentration-dependent in the range 25-150 µM and directly pH-related. In addition, a subtle but consistent inhibition of the intermediate-MW form of DPP-IV-like enzyme activity, ascribed to DPP-IV/CD26, observed only in human plasma and of the attractin (high-MW form of DPP-IV-like enzyme activity, expressed in U87 glioma cells) by the studied alkaloids was observed. We conclude that some of the QBA biological effects could be determined by tissue and cell type specific dipeptidyl peptidase IV-like molecules expression pattern.
Clinica Chimica Acta, Aug 1, 2010
Dipeptidyl peptidase-IV (DPP-IV) enzymatic activity controls biological halftime of multiple loca... more Dipeptidyl peptidase-IV (DPP-IV) enzymatic activity controls biological halftime of multiple local mediators. Its deregulation is associated with pathogenesis of several autoimmune diseases, including rheumatoid arthritis (RA). Although DPP-IV is the canonical representative of the group, a number of other proteins have been shown to have similar enzymatic activity. This study was aimed to identify the molecular source of DPP-IV activity in synovial fluid (SF) and fluid mononuclear cells (FMNC) in patients with RA and osteoarthritis (OA). In addition, the association of DPP-IV and the concentration of stromal cell-derived factor-1alpha (SDF), DPP-IV substrate, were evaluated. DPP-IV activity was measured by the kinetic fluorimetric method. The expression of studied molecules in FMNC and their concentrations in SF were assayed using flow cytometry and ELISA respectively. DPP-IV activity in SF, dominantly derived from the canonical DPP-IV, does not significantly differ between RA and OA. However, a significantly lower DPP-IV activity and expression in FMNC was found in RA as opposed to OA patients. Negative correlation between SDF concentration in SF and the relative amount of CD3+CD26+ cells was observed. We report decreased presence of DPP-IV/CD26 in CD3+ FMNC in RA, which also may participate on impaired balance of SDF concentration in SF.
PubMed, Feb 1, 2010
Meningiomas are tumors derived from arachnoid cap cells that represent approximately 30% of all i... more Meningiomas are tumors derived from arachnoid cap cells that represent approximately 30% of all intracranial tumors. In this study, we investigated 22 human meningiomas for the expression of dipeptidyl peptidase (DPP)-IV activity and/or structure homologs (DASH), including canonical DPP-IV/CD26, fibroblast activation protein-alpha (FAPalpha), DPP8 and DPP9. DPP-IV-like enzymatic activity, including all enzymatically-active DASH molecules, was found in all 18 benign meningiomas WHO grade I and IV atypical meningiomas WHO grade II by continuous rate fluorimetric assay in tissue homogenates and catalytic enzyme histochemistry in situ. In atypical meningiomas, this activity was significantly higher and was associated with higher cell proliferation as detected by Ki67 antigen immunohistochemistry. The expression of DPP-IV/CD26 and FAPalpha demonstrated by real-time RT-PCR and immunohistochemistry was low. As shown histochemically, it occurred most often on the surface of fibrous bundles and whorls rich in extracellular matrix. Compared to DPP-IV/CD26 and FAPalpha, the expression of DPP8 and DPP9 was higher and, in addition, it was present also in the cells inside these structures. Expression of CXCR4, the receptor of pro-proliferative chemokine stromal cell-derived factor-1alpha (SDF-1alpha), DPP-IV substrate, was found in all tumors, suggesting higher values in atypical grade II samples. This is the first report on the expression status of dipeptidyl peptidase-IV and related molecules in meningiomas. It shows that DPP8 and DPP9 prevail over canonical DPP-IV/CD26 and FAPalpha in all examined patients. In addition, the study suggests an increase of DPP-IV-like enzymatic activity in these tumors of WHO grade II.
Biochemical and Biophysical Research Communications, Sep 1, 2017
Human tumor xenografts in mice together with the species-specific analysis of expressed genes all... more Human tumor xenografts in mice together with the species-specific analysis of expressed genes allow to study the molecular processes driving tumor growth and progression in vivo and help to develop and evaluate anticancer therapies. In the present work, we designed and validated species-specific real-time RT-PCR assays for discrimination and quantitation of expression of human and mouse transcripts in cancer and stromal cells including dipeptidyl peptidase (DPP) 4, DPP8, DPP9, fibroblast activation protein (FAP) and CXC chemokine receptor 4 in mixed human-mouse biological samples. Using single species RNA samples and mixed human-mouse RNA samples, we formulated and characterized two-step realtime RT-PCR assays to quantitate expression of the indicated transcripts and described analytical performance of the assays. We also demonstrated the applicability of these assays for species-specific quantitation of transcriptional expression of mouse stromal cell genes including Dpp4, Dpp8, Dpp9, Fap and Cxcr4 in mixed human-mouse RNA samples from human glioma cell-derived tumor xenografts growing in mouse brain.
PubMed, 1995
A series of C-terminal linear endothelin analogues were prepared and their activities in C6 rat g... more A series of C-terminal linear endothelin analogues were prepared and their activities in C6 rat glioma cell line were tested. Among the synthetic analogues, IBDP 064, Fmoc-Leu-Asp-Ile-Ile-Trp-OH, was the most potent and selective inhibitor of endothelin-3-induced cell proliferation. Its action was comparable with that of the previously described peptide IRL 1038, [Cys11-Cys15]-ET-1(11-21), an ETB specific inhibitor.
PubMed, Jul 1, 2012
γ-Glutamyltranspeptidase (GGT, syn. γ-Glutamyltransferase) and dipeptidylpeptidase-IV (DPP-IV) ac... more γ-Glutamyltranspeptidase (GGT, syn. γ-Glutamyltransferase) and dipeptidylpeptidase-IV (DPP-IV) activity participates in metabolic and growth control of normal and tumor cells by processing biologically active peptides. Here, we report on up-regulation of these enzymes in human brain gliomas determined by catalytic enzyme histochemistry and immunocytochemistry. Higher activity of GGT was found in 50%, 68% and 81% of WHO grade II, III and IV tumors, respectively. The process started at/near the microvasculature, from where it spread to the parenchyma. On average, the enzyme activity in grade II, III and IV gliomas exceeded controls 2.0, 3.0 and 3.5-fold, respectively. Up-regulation of DPP-IV-like activity also started at the microvasculature, but mainly in pericytes and mononuclear-like cells around the vessels and dispersed in the parenchyma. Marked elevation of this enzyme activity, comprising also tumor parenchyma, occurred only in grade IV glioblastomas (65% patients; 3.6 times above controls) which can, therefore, help in their differentiation from grade III gliomas. The increase of total DPP-IV-like activity also included its two enzymatic homologs, the canonical DPP-IV/CD26 and FAP-1α. The increase in GGT is supposed to be a tumor grade dependent response of microvasculature and tumor astrocytes to stress induced by tissue hypoxia and/or the metabolic aberrancies. The increase in DPP-IV-like activity in high-grade tumors can be attributed to inflammatory/scavenging processes performed by the mononuclear-like cells and, in glioblastomas, also to regressive changes in the structure and function of the microvasculature and tumor parenchyma, including astrocyte stress response. The inverse relationship between DPP-IV-like activity and Ki67 in most glioblastomas and shorter survival time of patients with low activity of this enzyme also suggest its anti-oncogenic effects.
Neuro-Oncology
BACKGROUND Brain metastases (BM) are a common complication of oncologic disease associated with d... more BACKGROUND Brain metastases (BM) are a common complication of oncologic disease associated with dismal prognosis and there is an urgent need for novel therapeutic approaches. Fibroblast activation protein (FAP), a transmembrane serine protease, is an emerging theranostic target in cancer due to its frequent upregulation in the tumour microenvironment. FAP protein itself and/or FAP+ cells were shown to promote cancer progression in several extracranial malignancies. However, very little is known about the expression of FAP and the role of FAP+ cells in the unique microenvironment of BM. In this study, we quantified FAP expression and characterized FAP+ cells in BM of various origin. MATERIAL AND METHODS FAP enzymatic activity and protein concentration were determined in samples of BM (n=58) and control non-tumorous brain tissue (n=12) by an enzymatic assay using a specific fluorogenic substrate, western blot, and ELISA. Expression of FAP and the characteristics of FAP+ cells were ana...
Biomarker research, Feb 1, 2024
Small noncoding RNAs play an important role in various disease states, including cancer. PIWI pro... more Small noncoding RNAs play an important role in various disease states, including cancer. PIWI proteins, a subfamily of Argonaute proteins, and PIWI-interacting RNAs (piRNAs) were originally described as germline-specific molecules that inhibit the deleterious activity of transposable elements. However, several studies have suggested a role for the piRNA-PIWI axis in somatic cells, including somatic stem cells. Dysregulated expression of piRNAs and PIWI proteins in human tumors implies that, analogously to their roles in undifferentiated cells under physiological conditions, these molecules may be important for cancer stem cells and thus contribute to cancer progression. We provide an overview of piRNA biogenesis and critically review the evidence for the role of piRNA-PIWI axis in cancer stem cells. In addition, we examine the potential of piRNAs and PIWI proteins to become biomarkers in cancer.
Background: Dipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of se... more Background: Dipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of several autoimmune diseases. The aim of this study was to evaluate the association of DPP-IV presence in blood plasma and mononuclear cells with the disease activity in rheumatoid arthritis (RA). Methods: Patients with active RA (n = 27) were examined at the study enrolment and a follow-up examination was performed after the regression of the joint effusions and at least 6 months after the first investigation. The control group comprised patients with a noninflammatory joint disease, i.e. osteoarthritis (OA; n = 15). The DPP-IV-like enzymatic activity was measured by a kinetic fluorimetric method, the concentration of DPP-IV in the blood plasma was determined using ELISA and the expression of DPP-IV in leukocytes was assayed by flow cytometry. Results: Blood plasma DPP-IV-like enzymatic activity (median ± SD 220.15 ± 83.6 pkat/mL in RA vs. 376.9 ± 144.9 pkat/mL in OA, p < 0.001) and concentrations (median ± SD 465.1 ± 215.6 ng/mL in RA vs. 953.3 ± 368.4 ng/mL in OA, p < 0.001) were lower in patients with active RA compared to OA. In RA patients, the blood plasma DPP-IV-like enzymatic activity negatively correlated with the CRP concentration (r = −0.39, p = 0.044). No significant differences were observed in the DPP-IV-like enzymatic activity and DPP-IV expression in blood mononuclear cells between the RA and OA groups. At follow-up, 18 RA patients had a less active disease as demonstrated by an improved DAS28 score. In this group, comparison of the entry and the follow-up values in individual patients revealed an increase of the blood plasma DPP-IV-like enzymatic activity (median ± SD 141 ± 46 % of the patient's entry values, p = 0.011) and DPP-IV concentration (median ± SD 168 ± 25 %, of the patient's entry values, p = 0.033). In contrast to the blood plasma, the DPP-IV expression in blood mononuclear cells was reduced in these patients as evidenced by a decrease in the cell surface DPP-IV-like enzymatic activity as well as the median fluorescence intensity of DPP-IV staining in lymphocytes (median ± SD 66 ± 56 %, p = 0.018 and 63 ± 31 % of the patient's entry values, p = 0.005, respectively). Conclusions: The association between RA activity and the changes in blood plasma and blood mononuclear cell DPP-IV in individual patients supports the possible relationship of DPP-IV to RA pathophysiology.
Východiska: Multiformni glioblastom (GBM) je nejcastěji se vyskytujici intrakranialni malignitou ... more Východiska: Multiformni glioblastom (GBM) je nejcastěji se vyskytujici intrakranialni malignitou astrocytarniho původu u dospělých. Toto nadorove onemocněni je charakterizovano infaustni prognozou, ktera je způsobena předevsim znacnou rezistenci k adjuvantni terapii souvisejici do znacne miry s přitomnosti glioblastomových kmenových buněk (GSC). Cilena regulace GSC by mohla být novým terapeutickým přistupem vedoucim k překonani rezistence a lepsi prognoze u pacientů s GBM. Jednim z přistupů jak uspěsně ovlivňovat biologii GSC je jejich regulace skrze mikroRNA (miRNA). Tyto kratke nekodujici RNA molekuly posttranskripcně reguluji expresi vice než 2/3 vsech lidských genů, ktere jsou mimo jine zapojeny v regulaci signalnich drah asociovaných s kmenovými buňkami. Navic deregulace exprese některých miRNA byla pozorovana u mnoha nadorů, vc. GBM. Material a Metody: Pomoci technologie GeneChip miRNA 4.0 Array (Affymetrix) jsem provedli globalni expresni analýzu miRNA u 10 parových primarnich buněcných GBM linii derivovaných jednak v bezserových podminkach a v mediu s přidavkem 10 % FBS. Výsledky: Analýza Sox-2 pozitivnich a negativnich parových GBM buněcných linii odhalila 431 odlisně exprimovaných miRNA, přicemž 51 miRNA vykazovalo významnost nižsi než 0,001. U 25 miRNA byla pozorovana zvýsena a u 26 miRNA naopak snižena exprese v Sox-2 pozitivnich buňkach. Nasledně bylo zjistěno, že miR-192-5p a miR-885-5p predikovaly přeživani u pacientů s GBM. Nizka exprese miR-192-5p byla významně asociovana jak s delsim casem do progrese onemocněni (PFS) (0,003; log-rank test), tak s celkovým přeživanim (OS) pacientů s GBM (0,010; log-rank test). Kombinace exprese miR-192-5p a miR-885-5p pak byla schopna stratifikovat pa cienty na zakladě jak PFS, tak OS mnohem přesněji (PFS 0,007 a OS 0,008; log-rank test), než tomu bylo v připadě samotne miR-195-5p. Zavěr: GSC jsou obecně považovany za jednu z přicin rezistence GBM ke konvencni terapii. Zjistili jsme, že expresni hladiny miR-192-5p a miR-885-5p jsou zvýseny v Sox-2 pozitivnich GBM buňkach, což naznacuje jejich možne zapojeni do regulace GSC. Exprese obou těchto miRNA rovněž významně koreluje s přeživanim pa cientů s GBM. Tyto data tedy naznacuji, že miR-192-5p a miR-885-5p mohou být nejen prognostickými markery, ale take slibnými terapeutickými cili u pacientů s GBM.
Kluwer Academic Publishers eBooks, Dec 29, 2005
BMC Musculoskeletal Disorders, Sep 9, 2015
Background: Dipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of se... more Background: Dipeptidyl peptidase-IV (DPP-IV) is suggested to contribute to the pathogenesis of several autoimmune diseases. The aim of this study was to evaluate the association of DPP-IV presence in blood plasma and mononuclear cells with the disease activity in rheumatoid arthritis (RA). Methods: Patients with active RA (n = 27) were examined at the study enrolment and a follow-up examination was performed after the regression of the joint effusions and at least 6 months after the first investigation. The control group comprised patients with a noninflammatory joint disease, i.e. osteoarthritis (OA; n = 15). The DPP-IV-like enzymatic activity was measured by a kinetic fluorimetric method, the concentration of DPP-IV in the blood plasma was determined using ELISA and the expression of DPP-IV in leukocytes was assayed by flow cytometry. Results: Blood plasma DPP-IV-like enzymatic activity (median ± SD 220.15 ± 83.6 pkat/mL in RA vs. 376.9 ± 144.9 pkat/mL in OA, p < 0.001) and concentrations (median ± SD 465.1 ± 215.6 ng/mL in RA vs. 953.3 ± 368.4 ng/mL in OA, p < 0.001) were lower in patients with active RA compared to OA. In RA patients, the blood plasma DPP-IV-like enzymatic activity negatively correlated with the CRP concentration (r = −0.39, p = 0.044). No significant differences were observed in the DPP-IV-like enzymatic activity and DPP-IV expression in blood mononuclear cells between the RA and OA groups. At follow-up, 18 RA patients had a less active disease as demonstrated by an improved DAS28 score. In this group, comparison of the entry and the follow-up values in individual patients revealed an increase of the blood plasma DPP-IV-like enzymatic activity (median ± SD 141 ± 46 % of the patient's entry values, p = 0.011) and DPP-IV concentration (median ± SD 168 ± 25 %, of the patient's entry values, p = 0.033). In contrast to the blood plasma, the DPP-IV expression in blood mononuclear cells was reduced in these patients as evidenced by a decrease in the cell surface DPP-IV-like enzymatic activity as well as the median fluorescence intensity of DPP-IV staining in lymphocytes (median ± SD 66 ± 56 %, p = 0.018 and 63 ± 31 % of the patient's entry values, p = 0.005, respectively). Conclusions: The association between RA activity and the changes in blood plasma and blood mononuclear cell DPP-IV in individual patients supports the possible relationship of DPP-IV to RA pathophysiology.
Cancers, Apr 21, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
InTech eBooks, Feb 27, 2013
Biological Chemistry, 1998
... The pH activity profiles with GP-NHMec, which were completely inverse to the pro-files of DPP... more ... The pH activity profiles with GP-NHMec, which were completely inverse to the pro-files of DPP-II from cultured normal rat glial cells (Stevens et a/., 1987) and rat brain (Mentlein and Struckhoff, 1989 ... Kreisel, W., Heussner, R., Volk, B., Büchsel, R., Reutter, W., and Grok, W. (1982 ...
The International Journal of Biochemistry & Cell Biology, Mar 1, 2004
... Petr Bu ek , Radek Malík and Aleksi edo Corresponding Author Contact Information , E-mail The... more ... Petr Bu ek , Radek Malík and Aleksi edo Corresponding Author Contact Information , E-mail The Corresponding Author , E-mail The ... Interestingly, glycosylation seems to be a prerequisite for enzymatic activity of human recombinant NAALADase ([Barinka et al., 2002]), although ...
Biochemical Society Transactions, 2000
Neuro-Oncology, Sep 1, 2021
PubMed, Feb 24, 2016
Pancreatic cancer (PC) behaves very differently in comparison with other malignancies. Its preval... more Pancreatic cancer (PC) behaves very differently in comparison with other malignancies. Its prevalence continuously increases, mortality does not decrease, diagnosis is frequently late, radical surgery is limited to 15-20 % of patients, postoperative relapses are frequent, and chemotherapy has a palliative character. Preventive programs are the only possibility of improvement. In familial pancreatic cancer (FPC) the knowledge of the genetic mutation enables earlier entry of specialists into the surveillance program. The repeated use of high resolution imaging methods (including endoscopy and pancreatic cytology) may be followed by more frequent detection of the precursors and earlier stages of FPC. The identification of sporadic pancreatic cancer (SPC) depends fully on the construction of a multi-step and multi-disciplinary preventive program.
Physiological Research, 2003
Quaternary benzo[c]phenanthridine alkaloids (QBA), fagaronine (FA), sanguinarine (SA), chelerythr... more Quaternary benzo[c]phenanthridine alkaloids (QBA), fagaronine (FA), sanguinarine (SA), chelerythrine (CHE) and the QBA extract from Macleya cordata (EX) exerted differential inhibitory effect on the hydrolytic activity of particular dipeptidyl peptidase (DPP)-like enzyme isolated from human blood plasma and from human and rat glioma cell lines. The low-MW form of DPP-IV-like enzyme activity, corresponding most probably to DPP-8, observed only in glioma cells but not in human plasma, was inhibited preferentially by SA, CHE and EX, and only slightly by FA. The alkaloid inhibitory effect was concentration-dependent in the range 25-150 µM and directly pH-related. In addition, a subtle but consistent inhibition of the intermediate-MW form of DPP-IV-like enzyme activity, ascribed to DPP-IV/CD26, observed only in human plasma and of the attractin (high-MW form of DPP-IV-like enzyme activity, expressed in U87 glioma cells) by the studied alkaloids was observed. We conclude that some of the QBA biological effects could be determined by tissue and cell type specific dipeptidyl peptidase IV-like molecules expression pattern.
Clinica Chimica Acta, Aug 1, 2010
Dipeptidyl peptidase-IV (DPP-IV) enzymatic activity controls biological halftime of multiple loca... more Dipeptidyl peptidase-IV (DPP-IV) enzymatic activity controls biological halftime of multiple local mediators. Its deregulation is associated with pathogenesis of several autoimmune diseases, including rheumatoid arthritis (RA). Although DPP-IV is the canonical representative of the group, a number of other proteins have been shown to have similar enzymatic activity. This study was aimed to identify the molecular source of DPP-IV activity in synovial fluid (SF) and fluid mononuclear cells (FMNC) in patients with RA and osteoarthritis (OA). In addition, the association of DPP-IV and the concentration of stromal cell-derived factor-1alpha (SDF), DPP-IV substrate, were evaluated. DPP-IV activity was measured by the kinetic fluorimetric method. The expression of studied molecules in FMNC and their concentrations in SF were assayed using flow cytometry and ELISA respectively. DPP-IV activity in SF, dominantly derived from the canonical DPP-IV, does not significantly differ between RA and OA. However, a significantly lower DPP-IV activity and expression in FMNC was found in RA as opposed to OA patients. Negative correlation between SDF concentration in SF and the relative amount of CD3+CD26+ cells was observed. We report decreased presence of DPP-IV/CD26 in CD3+ FMNC in RA, which also may participate on impaired balance of SDF concentration in SF.
PubMed, Feb 1, 2010
Meningiomas are tumors derived from arachnoid cap cells that represent approximately 30% of all i... more Meningiomas are tumors derived from arachnoid cap cells that represent approximately 30% of all intracranial tumors. In this study, we investigated 22 human meningiomas for the expression of dipeptidyl peptidase (DPP)-IV activity and/or structure homologs (DASH), including canonical DPP-IV/CD26, fibroblast activation protein-alpha (FAPalpha), DPP8 and DPP9. DPP-IV-like enzymatic activity, including all enzymatically-active DASH molecules, was found in all 18 benign meningiomas WHO grade I and IV atypical meningiomas WHO grade II by continuous rate fluorimetric assay in tissue homogenates and catalytic enzyme histochemistry in situ. In atypical meningiomas, this activity was significantly higher and was associated with higher cell proliferation as detected by Ki67 antigen immunohistochemistry. The expression of DPP-IV/CD26 and FAPalpha demonstrated by real-time RT-PCR and immunohistochemistry was low. As shown histochemically, it occurred most often on the surface of fibrous bundles and whorls rich in extracellular matrix. Compared to DPP-IV/CD26 and FAPalpha, the expression of DPP8 and DPP9 was higher and, in addition, it was present also in the cells inside these structures. Expression of CXCR4, the receptor of pro-proliferative chemokine stromal cell-derived factor-1alpha (SDF-1alpha), DPP-IV substrate, was found in all tumors, suggesting higher values in atypical grade II samples. This is the first report on the expression status of dipeptidyl peptidase-IV and related molecules in meningiomas. It shows that DPP8 and DPP9 prevail over canonical DPP-IV/CD26 and FAPalpha in all examined patients. In addition, the study suggests an increase of DPP-IV-like enzymatic activity in these tumors of WHO grade II.
Biochemical and Biophysical Research Communications, Sep 1, 2017
Human tumor xenografts in mice together with the species-specific analysis of expressed genes all... more Human tumor xenografts in mice together with the species-specific analysis of expressed genes allow to study the molecular processes driving tumor growth and progression in vivo and help to develop and evaluate anticancer therapies. In the present work, we designed and validated species-specific real-time RT-PCR assays for discrimination and quantitation of expression of human and mouse transcripts in cancer and stromal cells including dipeptidyl peptidase (DPP) 4, DPP8, DPP9, fibroblast activation protein (FAP) and CXC chemokine receptor 4 in mixed human-mouse biological samples. Using single species RNA samples and mixed human-mouse RNA samples, we formulated and characterized two-step realtime RT-PCR assays to quantitate expression of the indicated transcripts and described analytical performance of the assays. We also demonstrated the applicability of these assays for species-specific quantitation of transcriptional expression of mouse stromal cell genes including Dpp4, Dpp8, Dpp9, Fap and Cxcr4 in mixed human-mouse RNA samples from human glioma cell-derived tumor xenografts growing in mouse brain.